Abstract: Described herein are substrates, sensors and systems related to measuring the concentration of an analyte such as hydrogen ion in a sample. Redox active moieties whose reduction and/or oxidation potentials are sensitive to the presence of an analyte are immobilized onto a silicon surface. Immobilized redox active moieties whose reduction and/or oxidation potential are insensitive to the analyte can be used for reference. Voltammetric measurements made using such modified silicon surfaces can accurately determine the presence and/or concentrations of analytes in a sample of interest. The silicon electrochemical sensors of the invention are robust and can be made so as not to require calibration or re-calibration.

Abstract: A sensing device for the determination of ions in a thin layer sample (32) comprising: a first (12) and second (14) ion selective electrode, each having a first (16) and second layer (20); the first layer (16) of the first ion selective electrode (12) being a polymeric membrane layer in electrical contact with the second layer (20) of the first ion selective electrode (12), and the first layer (18) of the second ion selective electrode (14) being a polymeric membrane layer in electrical contact with the second layer (20) of the second ion selective electrode (14); the first and second ion selective electrodes being positioned in opposing arrangement such that, the respective polymeric membrane layers are in direct contact with a thin layer sample (32) containing ions, located between the first and second electrodes; and a detector (28) in electrical connection with the first (12) and second (14) ion selective electrodes.

Abstract: An electro-chemical sensor is described having one or more redox species sensitive to a certain analyte and one or more redox species that are insensitive to that analyte, for the purpose of making measurements in a downhole environment in aquifers or oilfield reservoirs.

Abstract: A low maintenance reference electrode has a liquid junction body with a multiplicity of micron-sized capillary channels extending through the body for transporting electrolyte to a test solution. A viscosity-increasing agent thickens the electrolyte to limit its flow to a rate on the order of microliters/day so that a few milliliters of electrolyte suffice to provide an extended electrode life.

Abstract: Devices for detecting an analyte comprising a redox active analyte sensitive material on a working electrode and computer assisted signal acquisition and processing.

Abstract: An amperometric oxygen sensor for sensing the partial pressure of oxygen is disclosed. The amperometric oxygen sensor having a multilayered body which comprises a plurality of oxygen ion conductor layers interposed between a plurality of oxygen-porous electrode layers. Oxygen from a sample gas enters porous cathode layer of the sensor, through the ion conductor diffuses to anode because of a potential difference, and then an amperometric current is measured, which is proportional to the partial pressure of the oxygen. The amperometric oxygen sensor further comprises a heating member embedded within the sensor body and a heating controller electrically connects with the heating member to heat and maintain the sensor at working temperature, about 500˜800° C. An electrical insulator layer, but not thermal insulator, is blocked between the heating member and the oxygen-porous electrode strips so as to prevent the amperometric current from electromagnetic field interference.

Abstract: Described herein are substrates, sensors and systems related to measuring the concentration of an analyte such as hydrogen ion in a sample. Redox active moieties whose reduction and/or oxidation potentials are sensitive to the presence of an analyte are immobilized onto a surface of an electrode. Immobilized redox active moieties whose reduction and/or oxidation potential are insensitive to the analyte can be used for reference. Voltammetric measurements made using such modified surfaces can accurately determine the presence and/or concentrations of analytes in a sample of interest. The electrochemical sensors of the invention are robust and can be made so as not to require calibration or recalibration.

Abstract: There is provided a sample preparation device and method for preparing a sample of liquid for detection of impurities. First (40) and second (38) electrodes are provided, located for immersion in a liquid under test. A semipermeable membrane (42) is positioned to protect the first electrode (40) from a body of liquid under test (32). The semipermeable membrane allows the liquid under test to pass therethrough to reach the first electrode, while preventing solids carried in the liquid from reaching the first electrode, the first electrode being positioned to affect the liquid under test in the vicinity of a sensor (36). Particular embodiments feature a hydrophilic membrane to protect the electrodes from suspended solids in the sample, a thin electrode assembly to achieve a faster response and the addition of a heater for temperature control to achieve consistent detection conditions and improved anti-fouling properties.

Abstract: A chloride ion-selective electrode comprises: a reference electrode in contact with a reference solution; and a chloride ion-selective membrane as the interface of a sample and the reference solution, wherein the chloride-ion selective membrane comprises a chloride ion ionophore, a chloride ion-exchange resin, a plasticizer, and a polymer matrix.

Abstract: Amperometric ceramic electrochemical cells comprise, in one embodiment, an electrolyte layer, a sensing electrode layer comprising a ceramic phase and a metallic phase, and a counter electrode layer, wherein the cell is operable in an oxidizing atmosphere and under an applied bias to exhibit enhanced reduction of oxygen molecules at the sensing electrode in the presence of one or more target gases such as nitrogen oxides (NOX) or NH3 and a resulting increase in oxygen ion flux through the cell. In another embodiment, amperometric ceramic electrochemical cells comprise an electrolyte layer comprising a continuous network of a first material which is ionically conducting at an operating temperature of about 200 to 550° C.; a counter electrode layer comprising a continuous network of a second material which is electrically conductive at an operating temperature of about 200 to 550° C.

Abstract: An ion sensor includes: a conductive base structure including a substrate and an electrode film formed on the substrate; a plurality of ion-sensitive nanorods protruding from the electrode film; and an encapsulant enclosing the conductive base structure, surrounding the ion-sensitive nanorods, and formed with a window for exposing the ion-sensitive nanorods. Each of the ion-sensitive nanorods has a conductive core and an ion-sensitive layer formed on and enclosing the conductive core. The ion-sensitive material exhibits an ion selectivity of absorbing an ion of interest thereon for inducing a surface potential corresponding to concentration of the ion of interest.

Abstract: Nanopore based ion-selective electrodes and methods of their manufacture as well as methods for their use are disclosed and described. The nanopore based ion-selective electrode can include a pore being present in a solid material and having a nanosize opening in the solid material, a metal conductor disposed inside the pore opposite the opening in the solid material, a reference electrode material contacting said metal conductor and disposed inside the pore, a conductive composition in contact with the reference electrode and disposed in the pore, and an ion-selective membrane. The ion-selective membrane can be configured to isolate the metal conductor, reference electrode material, and conductive composition together within the pore.

Abstract: The present invention relates to the synthesis of lipophilic or immobilized monobasic phosphate (H2PO4) ionophores (7, 8a, 8b and 11) to be used as ion recognition molecules for monobasic phosphate (H2PO4?) in the cocktail preparation of hydrophobic polymer membranes in ion selective electrode (ISE) or ion-sensitive field effect transistor (ISFET) chemical sensors for detection of monobasic phosphate (H2PO4) ionic species in soil, synthetic media, hydrophonic liquid, tree sap, ground water and rivers.

Abstract: Microelectrode comprising a body formed from electrically non-conducting material and including at least one region of electrically conducting material and at least one passage extending through the body of non-conducting material and the region of conducting material, the electrically conducting region presenting an area of electrically conducting material to a fluid flowing through the passage in use. An electrochemical cell which includes such a microelectrode is also disclosed.

Abstract: The invention relates to novel electropolymerisable monomers which are to be polymerised in an aqueous solution and comprise: an electropolymerisable pattern selected from acetylene, pyrrols, thiophenes, indols, anilines, azines, p-phenylene vinylenes, p-phenylenes, pyrenes, furanes, selenophenes, pyrridazines, carbazoles, acrylates, methacrylates and the derivatives thereof, and a metalloporphyrine which is substituted by at least two ionised or ionizable entities in an aqueous solution. The invention also relates to a method for the polymerization of such monomers, to the electroactive probe that can be obtained by the polymerization of such monomers, and to a method for detecting a target ligand in a biological sample using one such electroactive probe.

Abstract: A reference electrode, especially for a potentiometric measuring cell, comprising: a housing, which surrounds a housing interior, which contains a reference electrolyte and at least a part of a sensing system for sensing a potential of the reference electrode. The reference electrolyte is in contact with a medium surrounding the housing, especially a measured medium, via at least one bore traversing through a housing wall of the housing, and wherein the bore has an inner diameter of no more than 50 ?m at its narrowest point and a length of no more than 200 ?m.

Abstract: There is provided a sample preparation device and method for preparing a sample of liquid for detection of impurities. First (40) and second (38) electrodes are provided, located for immersion in a liquid under test. A semipermeable membrane (42) is positioned to protect the first electrode (40) from a body of liquid under test (32). The semipermeable membrane allows the liquid under test to pass therethrough to reach the first electrode, while preventing solids carried in the liquid from reaching the first electrode, the first electrode being positioned to affect the liquid under test in the vicinity of a sensor (36). Particular embodiments feature a hydrophilic membrane to protect the electrodes from suspended solids in the sample, a thin electrode assembly to achieve a faster response and the addition of a heater for temperature control to achieve consistent detection conditions and improved anti-fouling properties.

Abstract: A photo-catalyst ozone detector includes a base. A positive electrode and a negative electrode are respectively disposed on the base. A photo-catalyst coating is disposed on the base for connecting the positive electrode and the negative electrode, and reacting with the ozone to detect ozone consistency, wherein the photo-catalyst coating contains titanium dioxide.

Abstract: A biosensor containing ruthenium, measurement using the same, and the application thereof. The biosensor comprises an extended gate field effect transistor (EGFET) structure, including a metal oxide semiconductor field effect transistor (MOSFET), a sensing unit comprising a substrate, a layer comprising ruthenium on the substrate, and a metal wire connecting the MOSFET and the sensing unit.

Abstract: Provided is an ion sensor with which the concentration of ions in a solution can be determined without any reference electrode. The ion sensor is equipped with: a first electrode plate; a second electrode plate which has been disposed opposite the first electrode plate and has one or multiple openings; an ion-sensitive film continuously formed so that the film is interposed between the first electrode plate and the second electrode plate, blocks up one side of each opening of the second electrode plate, and extends from the end of that side of the opening to the outer surface of the second electrode plate through the inner wall surface of the opening; and a sensor support which supports the second electrode plate so that when the ion concentration of a test solution to be examined is determined, the ion-sensitive film comes into contact with the test solution only in the portions thereof that have been formed in each opening and on the outer surface of the second electrode plate.

Abstract: A combination electrode, including: A first tube; a measuring membrane, which sealedly closes the first tube to form a measuring chamber; a second tube, which surrounds the first tube and is connected borderingly with the first tube to form an annular reference chamber; a buffer solution located in the measuring chamber; an electrolyte solution located in the reference chamber; a first tapping electrode in contact with the buffer solution; and a second tapping electrode in contact with the electrolyte; wherein, additionally, arranged in the reference chamber is an axially shiftable, annular, sealing element, which bounds the volume occupied by the electrolyte solution, the sealing element is biased by means of an electrically conductive, elastic, deformation element, which surrounds the first tube, and the second tapping electrode is electrically connected with the deformation element, in order to tap the potential of the second electrode via the deformation element.

Abstract: A sensor for biomolecules or charged ions includes a substrate; a first node, a second node, and a third node located in the substrate; a gate dielectric located over the substrate, the first node, the second node, and the third node; a first field effect transistor (FET), the first FET comprising a control gate located on the gate dielectric, and the first node and the second node; and a second FET, the second FET comprising a sensing surface located on the gate dielectric, and the second node and the third node, wherein the sensing surface is configured to specifically bind the biomolecules or charged ions that are to be detected.

Abstract: An object of the present invention is to provide a complex material in which an ion conduction film is curved and deformed when a potential difference is applied, which is operated at small electric power, has a large deformation amount, quick response performances, large degree of freedom in shape, and is easy in control of deformation, while having strength and durability necessary for practical use and being excellent in an economical aspect. A conductive cloth (preferably having stretchability), which is made conductive through plating of metal on a cloth or metal complex implantation, is joined as an electrode to both surfaces of the ion conduction film (the film in which an ion exchange film or ion liquid is immersed) made of a fluororesin and the like. When the potential difference is applied, the ion conduction film is deformed.

Abstract: A gas sensor including a sensor element constituted by an oxygen-ion conductive solid electrolyte as a main component and detecting a predetermined gas component in a measurement gas includes: an external communication part having an opening opened to the outside, and introducing the measurement gas from the outside under a predetermined diffusion resistance; an internal space communicating with the external communication part; a first electrode formed on a surface of the internal space; a second electrode formed in a space different from the internal space; and a pumping cell operable to pump out oxygen existing in the internal space when a predetermined voltage is applied between the first electrode and the second electrode. The thickness of the external communication part is 50% or more and 100% or less of the thickness of the internal space.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: Disclosed herein is a reference electrode including an electrolyte containing an optically-active material, including: an electrode body provided at an end thereof with an electrolyte separation membrane and charged therein with an optically-active material and an electrolyte solution; an inner electrode disposed in the electrode body to be immersed in the electrolyte solution; and an absorbance measurement probe for transmitting light to the electrolyte solution and collecting reflected light waves, which is disposed in the electrode body to be immersed in the electrolyte solution. Since the concentration of an electrode reaction material, such as Cl?, in the electrolyte is calculated using the absorbance of the electrolyte solution containing the optically-active material, the change in potential of the reference electrode can be properly corrected even when the reference electrode is exposed to a test environment for a long period of time and thus the concentration of the electrolyte changes.

Abstract: Electrochemical methods and materials for the detection of arsenic. In one aspect, arsenic is detected using a working electrode comprising particulate platinum. In another aspect, arsenic is detected using an electrode comprising indium tin oxide and particulate gold. Also provided are methods for the production of electrodes which involve the electrodeposition of gold onto indium tin oxide.

Abstract: An electrochemical sensor for detecting the concentration of ions in a solution includes a substrate, a sensor unit, and a reference electrode. The sensor unit includes at least one working electrode. The working electrode has a conductive layered structure formed on the substrate, and a sensor element of a metal oxide film formed on the conductive layered structure and capable of reacting with the ions in the solution to generate a potential. The reference electrode is spaced apart from the working electrode, and includes a conductive film printed on the substrate for establishing a potential difference between the working electrode and the reference electrode when the electrochemical sensor is brought into contact with the solution.

Abstract: The invention relates to a method of determining a charged particle concentration in an analyte (100), the method comprising steps of: i) determining at least two measurement points of a surface-potential versus interface-temperature curve (c1, c2, c3, c4), wherein the interface temperature is defined as a temperature of the interface between a measurement electrode and the analyte (100), wherein the surface-potential is defined at the interface, and ii) calculating the charged particle concentration from locations of the at least two measurement points of said curve (c1, c2, c3, c4).This method, which still is a potentiometric electrochemical measurement, exploits the temperature dependency of a surface-potential of a measurement electrode. The invention further provides an electrochemical sensor and electrochemical sensor system for determining a charged particle concentration in an analyte. The invention also provides various sensors which can be used to determine the charged particle concentration, i.e.

Abstract: The present invention discloses an ion sensitive field effect transistor, comprising: a GaN/sapphire layer, used as a substrate; an a-InN:Mg epilayer, deposited on the GaN/sapphire layer, used to provide a current path; a first metal contact, deposited on the a-InN:Mg epilayer to provide drain contact; and a second metal contact, deposited on the a-InN:Mg epilayer to provide source contact; and a patterned insulating layer, used to cover the first metal contact, the second metal contact and the a-InN:Mg epilayer, wherein the patterned insulating layer has a contact window defining an exposure area of the a-InN:Mg epilayer.

Abstract: An ion sensor includes a sensor main body having a channel for a sample and an opening connected to the channel, a responsive portion which is filled in the opening and selectively responds to a specific ion, an electrode which has a ring shape, is set such that a central axis of the ring is substantially perpendicular to a central axis of the channel, and senses the response, and an output terminal which is formed out of one metal plate out of which the electrode is formed, has a pin shape, and is held by the sensor main body such that an axis extends along a direction substantially perpendicular to the central axis of the channel and the central axis of the ring.

Abstract: A system for in situ monitoring within a specified environment includes a housing with an intake inserted into the environment. A plurality of pumps are included in the housing with a number of test beds, each being separately coupled to one of the number of pumps, where each of the number of test beds holds material and where each of the plurality of pumps operate to separately push fluid through a coupled test bed. An effluent storage device is disposed to receive effluent from the number of test beds.

Abstract: Micromachined reference electrodes for use in miniaturized electrochemical sensors, and methods for fabricating such reference electrodes and electrochemical sensors, for example, as a part of a microfluidic system, are disclosed. Electrochemical measurements allow for inexpensive detection of a wide variety of (bio-)chemical compounds in solution. The reference electrode is one of the main parts of an electrochemical cell. The reference electrode, from which no current is drawn, has a stable, constant potential.

Abstract: Apparatus (2) for monitoring chlorine in water (4), which apparatus (2) comprises a flow cell (6), the flow cell (6) containing a chlorine sensor (62) and an automatic calibration system, and the automatic calibration system being such that it comprises a small pair of in-line electrodes (50) for generating low concentrations of free chlorine, and injection means (44) for injecting in use of the apparatus a salt solution (64) of known concentration.

Abstract: A corrosion sensor 11A is installed on a tower 102, which is a structure such as a wind power generator, a substrate 12 of the corrosion sensor 11A is made of a material 13A, 13B, . . . identical to a material of each constituent member (such as a generator) of, for example, a wind power generator that is the structure, a coating film 16A is used to cover a plurality of conductive units 15 provided on a surface of the substrate 12 of the corrosion sensor 11A via insulating units 14, respectively, with the coating film 16A, and the coating film 16A identical to the coating film 16A applied onto the constituent member (such as a generator) is applied entirely onto an outer surface 102a of the tower 102 of the structure.

Abstract: In order to realize an accurate electrochemical measurement without a peak caused due to a silver chloride complex ion, an electrochemical measurement electrode of the present invention which measures an electrochemical active substance in a sample solution containing a chloride ion includes (i) a working electrode, (ii) a reference electrode made of silver and silver chloride, and (iii) a silver ion capturing material which captures a silver ion out of a silver chloride complex ion generated in the reference electrode.

Abstract: An electrochemical sensor utilises a chemical compound which is not a macromolecule but rather is a single chemical compound of determinate structure, incorporating two redox systems which differ in their response to a species to be detected. In one form, one redox system displays a voltammetric wave which is pH dependent while another displays a voltammetric wave which is pH independent and acts as an internal reference. The sensor comprises a solid substrate, which may be carbonaceous, on which the compound is immobilized. The sensor may be incorporated into a tool to be suspended in a wellbore.

Abstract: A wastewater analysis sensor cartridge (10) according to the invention is intended to be used only once. It has a liquid-tight housing (20), which contains at least one electrochemical sensor element (30, 32) and at least one reference element (56). Furthermore, the housing (20) contains a sensor element electrolyte tank (40,42) and a reference element electrolyte tank (44). The ion-sensitive membranes (31, 33) of the sensor elements (30, 32) and the housing (20) consist of plastic.

Abstract: A method for operating an ion-sensitive sensor with a measurement circuit which includes an ion-sensitive electrolyte-insulator-semiconductor structure (EIS); wherein the measurement circuit is embodied to issue an output signal which is dependent on ion concentration, especially a pH value, of a measured liquid; wherein the method comprises steps of: Introducing the ion-sensitive electrolyte-insulator-semiconductor structure into a measured liquid; accelerating charging processes in the region of an insulator layer of the ion-sensitive electrolyte-insulator-semiconductor structure by operating the sensor over a predetermined time span at least a first working point, dynamically adapting the working point to set a second working point, and registering and processing the output signal of the measurement circuit at the second working point.

Abstract: A water-proof electrochemical sensor for in situ analysis and real-time monitoring of chemical and biological compounds in a liquid analyte, such as a water column, or a water column/sediment interface, or sediment. The water-proof electrochemical sensor assembly comprises an electrode body that is resistant to high temperatures and pressure and includes a semi-hard o-ring or collar. A resilient elastomeric boot, that has an internal groove which is adapted to form a tight pressure-fit with the collar is installable on the electrode body. One end of the boot has an opening adapted to form an interference fit with a pin contact for electrical connections with external equipment and the other end of the boot has an opening adapted to form an interference fit with the electrode body whereby a water-proof seal is formed.

Abstract: An auto-calibration system for diagnostic test strips is described for presenting data individually carried on each test strip readable by a diagnostic meter. The carried data may include an embedded code relating to data particular to that individual strip. The data is presented so as to be read by a meter associated with the diagnostic test strip in order to avoid manually inputting the information.

Abstract: A NOx-decomposing electrode is provided having a certain or a high NOx-decomposing/reducing ability, which is formed on a third solid electrolyte layer for decomposing a NOx to produce oxygen. The detecting electrode contains a noble metal Pt, a material ZrO2 of the third solid electrolyte layer, and a mixture containing silica (SiO2) and alumina (Al2O3). Specifically, the detecting electrode contains 80% to 90% by weight of the Pt, 9.5% to 19.8% by weight of the ZrO2, and 0.2% to 0.5% by weight of the mixture containing silica and alumina.

Abstract: A chip integrated ion sensor is provided, which comprises a substrate having arranged thereon an electrolyte insulator semiconductor structure and a reference electrode. In particular, the electrolyte insulator semiconductor (EIS) structure may be formed on a chip already processed, i.e. the EIS structure may be formed in a Back End process on an already formed chip comprising a plurality of formed electronic components. In particular, the ion sensor may be adapted to form an ion concentration sensor, e.g. a pH sensor, i.e. may form a pH sensor. The reference electrode may be a non-polarizable electrode. In particular, the reference electrode may comprise Ag or AgCl as material.

Abstract: A microfabricated liquid junction reference electrode that can be integrated with microfabricated chemical or electrical sensors, which electrode is an M/MX type reference electrode comprised of a metal and a metal salt, as well as a X? Containing Ionic Liquid having a constant activity of X? and a porous thin-film membrane impregnated with a Hydrophobic Ionic Liquid.

Abstract: An electro-chemical sensor is described having two molecular redox systems sensitive to the same species and having an detector to detect relative shifts in the voltammograms of the two redox systems.

Abstract: A modular potentiometric sensor includes a housing having measuring and reference half-cells, a temperature sensor, and solution ground combination assembly. An electrical conductor of the combination assembly extends through the housing, while remaining electrically isolated from the housing and half-cells, terminating at an electrically and thermally conductive end cap. Seals at opposite ends of the housing permit portions of the half-cells and the combination assembly to extend therethrough. The seals, measuring half-cell, and the combination assembly define an electrolyte compartment for the reference half-cell. The end cap provides close thermal coupling to the test fluid while also serving as a test fluid ground that is electrically isolated from the electrolyte compartment.

Abstract: The present invention discloses a plastic potentiometric ion-selective sensor based on field-effect transistors which can be fabricated to form the miniaturized component via sputtering and/or printing method. A plastic potentiometric ion-selective sensor doesn't need an additional bias voltage to convert the signals. The disclosed plastic sensor comprises a plastic substrate, at least one working electrode formed on the plastic substrate, a reference electrode printed on the substrate, and a golden finger printed on the plastic substrate. The golden finger is for electrically coupling with the external world and for outward transmission of signals detected at the working electrode and the reference electrode. The disclosed plastic potentiometric ion-selective sensor is replaceable.

Abstract: Provided are a FET-based sensor for detecting an ionic material, an ionic material detecting device including the FET-based sensor, and a method of detecting an ionic material using the FET-based sensor. The FET-based sensor includes: a sensing chamber including a reference electrode and a plurality of sensing FETs; and a reference chamber including a reference electrode and a plurality of reference FETs. The method includes: flowing a first solution into and out of the sensing chamber and the reference chamber of the FET-based sensor; flowing a second solution expected to contain an ionic material into and out of the sensing chamber while continuously flowing the first solution into and out of the reference chamber; measuring a current in a channel region between the source and drain of each of the sensing and reference FETs; and correcting the current of the sensing FETs.

Abstract: Provided are fabrication, characterization and application of a nanodisk electrode, a nanopore electrode and a nanopore membrane. These three nanostructures share common fabrication steps. In one embodiment, the fabrication of a disk electrode involves sealing a sharpened internal signal transduction element (“ISTE”) into a substrate, followed by polishing of the substrate until a nanometer-sized disk of the ISTE is exposed. The fabrication of a nanopore electrode is accomplished by etching the nanodisk electrode to create a pore in the substrate, with the remaining ISTE comprising the pore base. Complete removal of the ISTE yields a nanopore membrane, in which a conical shaped pore is embedded in a thin membrane of the substrate.

Abstract: A pH sensor is provided. The pH sensor includes a body, a glass electrode, a reference electrode and a solution ground. The glass electrode is disposed on the body to contact a liquid sample. The reference electrode has a reference fill solution disposed within the body. The solution ground electrode is operably coupled to the body and has a portion of the solution ground electrode that is disposed within a harbor such that a portion of the solution ground electrode is configured to contact the liquid sample. The body has a passageway that extends from the reference fill solution to an aperture proximate the liquid sample.